The song's lyrics and, presumably, melody were written by one Colm Gallagher. Christy Moore says this in his autobiography/songbook "One Voice":

Colm Gallagher went to America a long time ago and he sings and plays in Los Angeles. I went to hear him play one night... I want to do a few more of his songs, particularly "Spanish Arches" and "Easter Lilies". He has many songs - I believe Tommy Makem has recorded a few.
He has another cracker about the St Patrick's Night Dance in San Fernando, with all the plastic paddies on the spree. I hope he's doing well and that we meet up again.

This from a review on Tommy Makem's website:

A ballad that hit home with Alaskan storytellers was the tragic "Peter Kagan and the Wind,"...after singing a host of traditional songs, both haunting and joyful, Makem took the audience by surprise with Colm Gallagher's irreverent "Bridie Murphy and the Kamikazi Pilot."
Anchorage Times

Also found a song called "Belfast Strike" on The Balladeers lyrics site... don't know if it's the same Colm Gallagher.

Cheers,
Michael